Pre-Treatment Ki67 Index for Everolimus Efficacy in Patients with Hormone Receptor-Positive and Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: A Multicenter Cohort Study.

Background:Everolimus is beneficial for patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2−) advanced breast cancer (ABC). However, some patients developed drug resistance and the well-established predictor for everolimus efficacy was limited.Objectives:The study was designed to evaluate the efficacy of everolimus in different treatment lines and identify several clinicopathological markers to estimate everolimus efficacy in patients with HR+/HER2− ABC.Design:This was a retrospective and multicenter study.Methods:Between 2014 and 2022, more than 2000 patients with tumors who received everolimus were collected from multiple cancer centers in China (National Cancer Center, Chinese PLA General Hospital, Peking University Cancer Hospital & Institute). A training cohort and two validation cohorts were developed.Results:The training cohort included 338 patients. The median progression-free survival (PFS) for everolimus was 5.6 months, with an objective response rate of 25.1% and a clinical benefit rate of 54.4%. PFS was significantly worse from first-line (1L) to second-line (2L) to third-line (3L), with PFS1L for 13.5 months, PFS2L for 6.1 months, and PFS3L for 4.1 months (p = 2.9e−6, hazard ratio (HR) = 0.70, 95% confidence interval (CI) = 0.61–0.82). The clinicopathological characteristics, including post-1L everolimus treatment, Ki67 index of more than 40%, more than two metastatic sites at first recurrence, and receiving adjuvant chemotherapy, were independent risk factors for PFS. A predictive model for everolimus efficacy was established using these four factors. In the low-risk group, patients achieved a median PFS of 12.6 months, significantly longer compared to 2.7 months for those in the high-risk group (p = 2.4e−64, HR = 9.41, 95% CI = 7.05–12.56). The area under the curve was 0.96, 0.95, and 0.94 for 6-month, 1-year, and 3-year PFS, respectively. Internal validation cohort (PFS 18.4 vs 3.1 months, p = 3.6e−11, HR = 3.78, 95% CI = 2.49–5.74) and external validation cohort (PFS 13.5 vs 3.1 months, p = 2.9e−10, HR = 11.53, 95% CI = 4.68–28.37) confirmed its power for estimating clinical benefits of everolimus.Conclusion:A predictive model was successfully established to predict survival outcomes for everolimus in patients with HR+/HER2− ABC, which may provide references for the management of everolimus in Chinese patients with HR+/HER2− ABC.

The phosphatidylinositol-3-kinase (PI3K) pathway is mutated and aberrantly activated in breast and other cancers and plays a key role in cancer cell proliferation and survival.1 2 The PI3K pathway is deregulated through a variety of mechanisms, including mutation or amplification of PI3K, loss or inactivation of the tumour suppressor phosphatase and tensin homolog deleted on chromosome 10 ( PTEN ), as well as activation of tyrosine kinase growth factor receptors or oncogenes upstream of PI3K.3 4 Activating mutations in PIK3CA , the gene encoding the alpha isoform (p110 α) catalytic subunit of PI3K, is present in up to 40% of patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancers5 6 and represents a molecular target to personalise therapy of selected patients with breast cancer.2 Standard of care therapy for advanced HR-positive/HER2-negative breast cancers consists on endocrine therapy with or without the use of cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors.7 Therapy-resistance inevitably occurs in the majority of patients. The rationale of combining PI3K inhibitors and endocrine therapy is to synergistically inhibit both the PI3K and ER pathways.8 Initial trials of pan-PI3K inhibitors plus endocrine therapy for patients with advanced breast cancer showed modest benefit with high rates of toxicity limiting their clinical drug development.9–11 Selective isoform-specific PI3K inhibitors, such as an α-specific PI3K inhibitor, have subsequently revealed activity with less toxicity.12 13 The phase III SOLAR-1 (Clinical Studies of Alpelisib in Breast Cancer 1) trial investigated the efficacy and safety of alpelisib, a α-specific class-I PI3Kinhibitor, plus fulvestrant versus placebo plus fulvestrant in patients with metastatic HR-positive/HER2-negative breast cancer who had received endocrine therapy beforehand.14 About 85.6% of patients …

Introduction: The phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) is found mutated (mut) in ~40% of patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer (ABC); some of these alterations can lead to PI3K pathway hyperactivation and are associated with endocrine resistance and poor prognosis in advanced disease. Alpelisib (ALP), an α-selective PI3K inhibitor and degrader, demonstrated clinical benefit in combination with fulvestrant (FUL) in the SOLAR-1 study in pts with PIK3CA-mut HR+, HER2− ABC. SOLAR-1 (NCT02437318) was a double-blind, placebo (PBO)-controlled, stratified, randomized (per PIK3CA-alt status as determined by QIAGEN PIK3CA RGQ PCR test), Phase III study of ALP in combination with FUL in pts with HR+, HER2− ABC who progressed on/after aromatase inhibitor therapy. Here, we compare the gene alteration landscape in pts with altered (alt) and non-alt PIK3CA and the efficacy of ALP + FUL in pts whose tumors have alterations in both selected genes or cell signaling pathways as well as PIK3CA-alt or non-alt status as determined by next-generation sequencing (NGS). Methods: In this analysis, retrospective NGS analysis using the FoundationOne CDx 324-gene panel was performed on available FFPE tissue samples. In all, 398 pts were categorized into 2 cohorts based on NGS-tested PIK3CA status. The PIK3CA-alt cohort comprised 237 patients (ALP, n=120; PBO, n=117); the PIK3CA-non-alt cohort 161 patients (ALP, n=81; PBO, n=80). Selected genes altered in >20 SOLAR-1 pts were investigated further. Clinical benefit was assessed by progression-free survival (PFS) based on gene alt status in the PIK3CA-alt and -non-alt cohorts. Hazard ratios (HR) for PFS were estimated using a multivariate Cox PH model by adjusting multiple clinical covariates including age, ECOG performance status, bone lesion, prior CDK4/6 inhibitor treatment, and lung/liver metastasis. Results: PIK3CA-alt and -non-alt cohorts had differential genomic landscapes; differential PFS benefit was observed among the genes analyzed, including ARID1A, EMSY, FGFR2, MAP3K1, MYC, RAD21, RAD51C, TP53, and a gene set associated with the MAPK pathway. In most pts with analyzed gene alterations, numerically longer PFS was observed with ALP vs PBO in the PIK3CA-alt cohort than the -non-alt cohort, particularly pts with alterations in ARID1A (median [m] PFS for ALP vs PBO in PIK3CA-alt cohort: 22.11 vs 12.42 mo, HR 0.48; vs mPFS in PIK3CA-non-alt cohort: 6.21 vs 22.31 mo, HR 1.33) and MAP3K1 (PIK3CA-alt cohort: 17.25 vs 7.70 mo, HR 0.50; vs PIK3CA-non-alt cohort: 9.17 vs 5.26 mo, HR 1.32). Full results are found in the Table. Results should be interpreted with caution, as analyses used small sample sizes and were not adjusted for multiple testing. Conclusions: A differential genomic landscape was observed in PIK3CA-alt and PIK3CA-non-alt populations. Clinical benefit of ALP vs PBO was observed in pts with PIK3CA-alt disease who also had alterations in analyzed genes and/or genes associated with the MAPK pathway. The data from this analysis suggest that, of the genes analyzed, only PIK3CA mutations can predict pt sensitivity to ALP. Table. PFS in PIK3CA-altered PIK3CA-non-altered populations by gene alteration Citation Format: Dejan Juric, Hope Rugo, Albert Reising, Chong Ma, Eva Ciruelos, Sibylle Loibl, Christian F. Singer, Joo Hyuk Sohn, Mario Campone, PierFranco Conte, Hiroji Iwata, Farhat Ghaznawi, Michelle Miller, Tetiana Taran, Faye Su, Fabrice Andre. Differential Gene Mutation Landscape in Patients With PIK3CA-altered and Non-altered Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-negative Advanced Breast Cancer in the SOLAR-1 Clinical Study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P5-02-32.

Background: AKT pathway activation has been implicated in the development of endocrine therapy resistance in hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2–) advanced breast cancer (ABC). In the Phase II, placebo (PBO)-controlled FAKTION trial, the addition of the pan-AKT inhibitor capivasertib to fulvestrant significantly improved progression-free survival (PFS) and overall survival in postmenopausal women with aromatase inhibitor (AI)-resistant HR+/HER2– ABC. The Phase III, randomized, double-blind, PBO-controlled CAPItello-291 trial (NCT04305496) investigated the efficacy and safety of capivasertib + fulvestrant in patients with AI-resistant HR+/HER2– ABC. Methods: Eligible pre/peri or postmenopausal women or men with HR+/HER2– ABC that had recurred or progressed on or after AI therapy with or without a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor were randomized 1:1 to receive fulvestrant (per standard dosing schedule) with either PBO or capivasertib (400 mg twice daily; 4 days on, 3 days off). Randomization was stratified by the presence of liver metastases, prior use of CDK4/6 inhibitors, and geographic location. AKT pathway alteration status (at least one qualifying PIK3CA, AKT1, or PTEN alteration) was determined using next-generation sequencing in tumor tissue. The dual primary endpoint was investigator-assessed PFS in the overall population and in patients with AKT pathway-altered tumors. Results: A total of 708 patients were randomized: 355 to capivasertib + fulvestrant and 353 to PBO + fulvestrant. Overall, 41% of patients had AKT pathway-altered tumors (48% [n=289/602] of patients with tumor sequencing results), 22% were pre/perimenopausal and 77% postmenopausal, with 1% male. Prior therapy for advanced disease included: 87% of patients with ≥1 line of prior treatment, 69% with a prior CDK4/6 inhibitor, and 18% with prior chemotherapy. Demographic and baseline characteristics were broadly balanced between the overall and altered populations and by treatment groups. At primary analysis (data cut-off Aug 15, 2022), 551 and 236 PFS events had occurred in the overall and pathway-altered populations, respectively. Overall, the median PFS was 7.2 months with capivasertib + fulvestrant and 3.6 months with PBO + fulvestrant (hazard ratio [HR] 0.60; 95% confidence interval [CI] 0.51–0.71; p<0.001). In patients with AKT pathway-altered tumors, median PFS was 7.3 months with capivasertib + fulvestrant and 3.1 months with PBO + fulvestrant (HR 0.50; 95% CI 0.38–0.65; p<0.001). The objective response rate in patients with measurable disease was 22.9% for capivasertib + fulvestrant vs 12.2% for PBO + fulvestrant overall and 28.8% vs 9.7% in the AKT pathway-altered population. The most frequent all-grade adverse events (AEs) with capivasertib + fulvestrant were diarrhea (72.4% vs 20.0% PBO + fulvestrant arm), rash (group term of rash, rash macular, rash maculo-papular, rash papular, rash pruritic; 38.0% vs 7.1%) and nausea (34.6% vs 15.4%). The most frequently reported grade ≥3 AEs were rash (group term; 12.1% vs 0.3%), diarrhea (9.3% vs 0.3%), and hyperglycemia (2.3% vs 0.3%); grade ≥3 stomatitis was 2.0% vs 0%. AEs leading to discontinuation of capivasertib/placebo were reported in 13.0% and 2.3% of patients, respectively. Conclusions: Capivasertib + fulvestrant significantly improved PFS compared to fulvestrant alone in the overall population, and in patients with AKT pathway-altered tumors, and may become a future treatment option in this setting. The safety profile of capivasertib + fulvestrant was generally manageable and consistent with prior data. Funding: CAPItello-291 is sponsored by AstraZeneca. Editorial acknowledgment: AstraZeneca-funded medical writing support was provided by Suzanne Patel, Ph.D., from BOLDSCIENCE Inc. Capivasertib was discovered by AstraZeneca subsequent to a collaboration with Astex Therapeutics (and its collaboration with the Institute of Cancer Research and Cancer Research Technology Limited). Citation Format: Nicholas Turner, Mafalda Oliveira, Sacha J. Howell, Florence Dalenc, Javier Cortés, Henry Gomez, Xichun Hu, Komal Jhaveri, Sibylle Loibl, Serafin Morales Murillo, Zbigniew Nowecki, Meena Okera, Yeon H. Park, Masakazu Toi, Lyudmila Zhukova, Chris Yan, Gaia Schiavon, Andrew Foxley, Hope Rugo. GS3-04 Capivasertib and fulvestrant for patients with aromatase inhibitor-resistant hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer: results from the Phase III CAPItello-291 trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr GS3-04.

This study aims to explore the role of the non-luminal disease score (NOLUS) for everolimus in patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer (ABC). NOLUS has previously been established as an algorithm: NOLUS (0-100) = - 0.45 × ER(%) - 0.28 × PR(%) + 0.27 × Ki67(%) + 73. Information of cancer patients was retrospectively collected from three cancer centers in China. Totally, 198HR+/HER2- ABC patients with complete records in expression rates (%) of ER, PR and Ki67 were enrolled in the study. The expression rates (%) of ER, PR, and Ki67 were 38.8 ± 27.9 versus 80.9 ± 14.2 (p < 0.001), 13.9 ± 14.3 versus 50.2 ± 30.4 (p < 0.001), and 37.8 ± 23.6 versus 28.7 ± 19.9 (p = 0.04), respectively, for NOLUS-positive patients and NOLUS-negative patients. For the overall population, the median PFS was 5.8 months versus 5.1 months in NOLUS-positive and NOLUS-negative patients (p = 0.16, HR = 0.75, 95% CI = 0.50, 1.12). The median 1L-, 2L, and 3L-PFS was 13.9 months versus 11.8 months (p = 0.22, HR = 1.63, 95% CI = 0.74, 3.62), 6.7 months versus 3.6 months (p = 0.08, HR = 0.34, 95% CI = 0.10, 1.18), and 4.6 months versus 4.0 months (p = 0.81, HR = 1.07, 95% CI = 0.63, 1.79) respectively, for NOLUS-positive patients and NOLUS-negative patients. NOLUS-positive patients have a lower percentage of ER and PR, but a higher percentage of Ki67 index. The correlation between thebenefits of everolimus and NOLUS failed to develop significance, suggesting that NOLUS may not be applicable in predicting everolimus efficacy in patients with HR+/HER2- ABC. Further research is expected.

Introduction: Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) is mutated in ~40% of patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer (ABC). PIK3CA mutations are associated with resistance to endocrine therapy (ET) and worse overall survival. Alpelisib (ALP), an α-selective PI3K inhibitor and degrader, is indicated in combination with fulvestrant (FUL) for pts with PIK3CA-mutated (mut) HR+, HER2− ABC following progression on/after ET-based treatments. In the Phase 2, open-label, 3-cohort, noncomparative BYLieve study, clinical benefit of ALP in combination with ET was observed in the post-cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) setting in pts with PIK3CA-mut, HR+, HER2− ABC. Here we report the results of a biomarker analysis using paired baseline (Cycle 1 Day 1) and end-of-treatment (EOT) circulating tumor DNA (ctDNA) samples from pts in BYLieve Cohorts A and B. Methods: In the BYLieve study, pts with PIK3CA-mut, HR+, HER2− ABC had CDK4/6i + aromatase inhibitor (Cohort A; N=127) or CDK4/6i + FUL (Cohort B; N=126) as treatment immediately prior to receiving ALP + FUL and ALP + letrozole, respectively. In this biomarker analysis, gene alterations were detected in ctDNA at baseline and EOT using next-generation sequencing (PanCancer V2 panel). Pts included in this interim analysis had confirmed PIK3CA mutations and matched baseline/EOT samples with enough sequencing coverage and ctDNA fraction to detect mutations at both time points. ctDNA fractions, tumor mutation burden (TMB) distributions, genomic landscapes, gain/loss of PIK3CA and estrogen receptor 1 (ESR1), chromosome 8/11 amplification profiles, and alterations in PI3K pathway and potential CDK4/6i resistance markers were assessed across time points. Sample sizes were small; results should thus be interpreted with caution. Results: Forty-three pts were included in the Cohort A biomarker population and 40 pts were included in Cohort B. ctDNA fraction was numerically higher at EOT compared with baseline in both cohorts; further analyses will be presented. In Cohort A, no significant differences were observed in TMB at EOT compared with baseline (P=0.21). In Cohort B, TMB was higher at EOT compared with baseline (P=0.053). Chromosome 8/11 amplifications were consistent between baseline and EOT for both cohorts. Small variations were observed in ESR1/PIK3CA mutations between baseline and EOT on both cohorts (Table). The status of potential CDK4/6i resistance markers was relatively unchanged at EOT (Table). Loss-of-function mutations in PTEN, a known PI3K inhibitor resistance marker, increased from 9% at baseline to 14% at EOT in Cohort A and from 12% at baseline to 22% at EOT in Cohort B. Conclusions: Between baseline and EOT, only small variations in gene alterations in PIK3CA-mutated HR+, HER2– ABC were observed in the post-CDK4/6i setting. As the disease progressed, increases in loss-of-function mutations in PTEN at EOT in both Cohorts A and B suggested loss of PTEN in PI3K pathway may drive resistance to ALP. Early intervention with ALP, when the tumor is particularly driven by PIK3CA oncogenic mutations and before it develops more genomic complexity, may potentially provide better clinical outcomes. Table. Gene Alteration Gain/Loss at Baseline/EOT Across Cohorts A and B Citation Format: Dejan Juric, Nicholas Turner, Sherene Loi, Fabrice Andre, Stephen K. Chia, Komal Jhaveri, Patrick Neven, Rebecca Dent, Eva Ciruelos, Mukta Joshi, Estelle Roux, Heather Patino, Murat Akdere, Hope Rugo. Baseline and End-of-Treatment Biomarkers in Patients With PIK3CA-Mutated, Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer From BYLieve Study Cohorts A and B [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-09-12.

PurposeThis meta-analysis aimed to assess the efficacy and safety of cyclin-dependent kinase (CDK) 4/6 inhibitors plus endocrine therapy (ET) in hormonal receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC).MethodsWe searched PubMed, Embase, Cochrane, ClinicalTrials.gov., ASCO, ESMO and AACR databases from inception to October 10, 2019 for randomized controlled trials (RCTs) that compared CDK 4/6 inhibitors plus ET to single-agent ET with no treatment-line restriction. The main outcomes analyzed were progression-free survival (PFS), overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR), and adverse events (AEs).ResultsOf 938 identified studies, 9 RCTs with 5043 women were eligible and included. Compared with ET alone, CDK 4/6 inhibitors and ET combination improved in PFS (hazard ratio (HR) 0.54, 95% confidence interval (CI) 0.50–0.59, p< 0.00001) and OS (HR 0.77, 95% CI 0.69–0.85, p< 0.00001), regardless of ET strategies (HR 0.54, 95% CI 0.50–0.59 in PFS; HR 0.77, 95% CI 0.69–0.85 in OS), treatment line of advanced disease (HR 0.52, 95% CI 0.46–0.59 in PFS; HR 0.75, 95% CI 0.66–0.85 in OS) and menopausal status (HR 0.54, 95% CI 0.50–0.58 in PFS; HR 0.76, 95% CI 0.68–0.84 in OS). Higher risk of grade 3/4 AEs (RR 2.66, 95% CI 2.44–2.90, p < 0.00001) were observed in the combination group than in the ET group.ConclusionsCombination therapy with CDK 4/6 inhibitors and ET prolongs survival in HR+/ HER2- ABC. This combination is a better therapeutic strategy than endocrine monotherapy in HR+/HER2- ABC, regardless of treatment line, menopausal status and other individual characteristics.

Background: Palbociclib in combination with endocrine therapy (ie, an aromatase inhibitor [AI] or fulvestrant) is a current standard of care for patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) advanced or metastatic breast cancer (ABC/mBC). Findings from the PALOMA clinical trials have shown that patients receiving palbociclib with AI or fulvestrant maintained stable quality of life (QoL). However, no data are currently available from real-world settings regarding patients’ QoL experiences while receiving palbociclib. Methods: This noninterventional, prospective, multicenter study evaluated female and male patients diagnosed with HR+/HER2- ABC/mBC and treated with palbociclib as indicated by the attending physician in the routine course of care. QoL was assessed using the European Organization for the Research and Treatment of Cancer Quality-of-Life Questionnaire Core 30 (EORTC QLQ-C30). The EORTC QLQ-C30 was collected at enrollment prior to receiving palbociclib (baseline), monthly for the first 3 months of treatment with palbociclib, and then every 3 months until the end of treatment or patient withdrawal or death. The EORTC QLQ-C30 could be completed using an interactive Web response system or a paper questionnaire. Here we report demographic characteristics and interim analysis of QoL assessments as measured by EORTC QLQ-C30 at baseline and at 3 and 6 months postbaseline. Descriptive analyses are presented for subscales of the EORTC QLQ-C30. Results: 522 patients who completed ≥6 months of palbociclib treatment as of May 20, 2019, were included in this interim analysis; 394 were prescribed palbociclib as first-line treatment. The remaining 128 patients initiated palbociclib in second and later lines. Median age at enrollment was 64 years, 98% of patients were female, and 83% were white. More than half of all patients (n=285) received palbociclib in combination with letrozole or anastrozole; of the remaining patients, 218 received palbociclib plus fulvestrant and 19 received palbociclib plus exemestane. Mean (SD) EORTC QLQ-C30 scores remained similar over the first 6 months of treatment: 66.2 (22.6) at baseline, 68.3 (19.7) at 3 months, and 70.2 (21.3) at 6 months. In addition, the mean scores for each functional scale and symptom scale on the EORTC QLQ-C30 also remained stable over the first 6 months (Table). With the exception of pain scores (which declined by 7 points), the change from baseline at 6 months generally was less than 5 points across the different subscales of EORTC QLQ-C30. Conclusions: The 522 patients examined in this interim analysis experienced stable to modestly improved QoL from baseline to 6 months after starting palbociclib. Changes from baseline in EORTC QLQ-C30 scores generally were below the 10-point threshold regarded as clinically meaningful. These early findings indicate that patients enrolled in the study have maintained their baseline QoL while being treated with palbociclib. Funding: Pfizer (NCT03280303) EORTC QLQ-C30Baseline3 Months6 MonthsGlobal Health/Quality of Life*n (missing)474 (48)292 (230)409 (113)Mean (SD) score66.2 (22.6)68.3 (19.7)70.2 (21.3)Functional scales score, mean (SD)*Physical functioning75.6 (23.3)75.8 (21.9)77.2 (21.4)Role functioning72.5 (31.9)76.7 (26.1)77.1 (26.8)Emotional functioning74.8 (22.8)77.7 (22.3)79.7 (20.5)Cognitive functioning78.8 (24.6)82.7 (20.6)80.1 (22.0)Social functioning76.4 (28.3)79.5 (25.5)81.5 (24.7)Symptom scales score, mean (SD)†Fatigue34.3 (25.7)35.0 (23.6)33.7 (22.2)Nausea and vomiting11.3 (20.2)10.4 (16.4)10.6 (19.3)Pain33.5 (30.0)27.3 (27.2)26.5 (26.9)Dyspnea22.2 (28.3)18.7 (22.5)18.8 (24.1)Insomnia29.3 (30.1)27.5 (31.7)27.4 (27.9)Appetite loss21.1 (27.9)19.4 (26.4)17.9 (26.5)Constipation18.4 (26.6)15.2 (23.8)16.0 (23.8)Diarrhea12.3 (22.1)12.0 (20.8)12.6 (22.0)Financial difficulties25.0 (32.4)23.9 (30.4)22.1 (29.5)*Higher scores indicate a better level of functioning. †Higher scores indicate more severe symptoms. Citation Format: Gabrielle Rocque, Joanne L Blum, Aldemar Montero, Ibrahim Nakhoul, Sobha Kurian, Richard C Frank, Bijoy Telivala, Mayank Ajmera, David Coblentz, Joseph C Cappelleri, Yao Wang, Debu Tripathy. Quality of life in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer treated with palbociclib in real-world practice settings [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD10-03.

Ribociclib plus fulvestrant for postmenopausal women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in the phase III randomized MONALEESA-3 trial: updated overall survival

Abemaciclib is a CDK4/6 inhibitor used to treat hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer. The prognostic value of patient-reported outcomes (PROs) has been minimally explored for treatment outcomes with CDK4/6 inhibitors. The performance of PROs compared with Eastern Cooperative Oncology Group performance status (ECOG-PS) is unknown. This study pooled data from single-arm trial, MONARCH 1, and randomized trials, MONARCH 2 and 3. In total, 900 patients initiated abemaciclib and 384 comparator therapy. Pretreatment PRO association with progression-free survival (PFS) was modeled using Cox proportional hazards regression. Prediction performance was assessed via the C-statistic (c). PROs were recorded via the European Organisation for Research and Treatment of Cancer QLQ-C30. Patient-reported physical function, pain, role function, fatigue, and appetite loss were associated with PFS on univariable and adjusted analysis (p < .05). Physical function (c = 0.55) was most predictive, superior to ECOG-PS (c = 0.54), with multivariable analysis indicating both provide independent information (p < .02). In the pooled randomized arms of MONARCH 2 and 3, the PFS treatment benefit (hazard ratio [95% confidence interval]) of abemaciclib (vs. comparators) was 0.75 (0.57-1.0) for low physical function, compared with 0.48 (0.40-0.59) for intermediate/high (p[interaction] = .01). PROs were identified as prognostic factors for PFS in patients initiating abemaciclib, with patient-reported physical function containing independent predictive information beyond ECOG-PS. Low physical function was associated with a decrease in the magnitude of PFS benefit from abemaciclib. PROs should be explored as prognostic, predictive, and stratification factors for clinical use and research trials of CDK4/6 inhibitors. For the first time, pretreatment patient-reported outcomes have been shown to be independent prognostic markers for progression-free survival (PFS) in patients diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer treated with abemaciclib. Importantly, patients with low physical function had a smaller PFS benefit from abemaciclib (vs. comparator) than patients with intermediate/high physical function. The present study demonstrates patient-reported outcomes as a simple, effective, inexpensive, and independent prognostic marker for patients with HR+/HER2- advanced breast cancer treated with abemaciclib.

BackgroundThis study aimed to identify factors affecting patients’ preferences for postmenopausal hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer treatments, their relative importance, and impact of sociodemographic/clinical characteristics.MethodsJapanese postmenopausal patients with HR+ breast cancer chose between 2 hypothetical treatments for HR+/HER2− advanced breast cancer using an online discrete choice experiment, defined by different levels of 5 attributes: progression-free survival (PFS), incidence of diarrhea (IOD), frequency of loose stools of grade 1–3 severity (FOS), duration of diarrhea (DOD), and route/frequency of administration (RFA). Conditional logit modeling identified relative preferences for each attribute. Subgroup analyses, based on sociodemographic characteristics (age, employment status, age of youngest child, marital status) and clinical characteristics (relapse/metastasis, hormone sensitivity), identified factors affecting preferences.ResultsOf 896 participants screened, 258 eligible participants were included in analyses. Patient preferences, when the potential frequency of diarrhea was grade 2, were (strongest to weakest): PFS, DOD, FOS, IOD, RFA; however, when the potential frequency of diarrhea was grade 3, FOS became most important. Sociodemographic/clinical characteristics tended to affect preferences.ConclusionsJapanese postmenopausal patients with HR+ breast cancer preferred treatments that extend PFS despite potential grade 2 diarrhea. However, when diarrhea severity increased to grade 3, patients were more willing to sacrifice PFS to avoid more frequent diarrhea. Prevention or limitation of diarrhea to grade ≤ 2 is important for maintaining patients’ motivation for treatment that can extend PFS. Additionally, patient characteristics (age, family context, therapeutic experience) should be considered during treatment choice.

BackgroundIn MONARCH 2, abemaciclib plus fulvestrant significantly improved median progression-free survival (PFS, 16.4 vs 9.3 months, hazard ratio [HR] 0.553) and overall survival (OS, 46.7 vs 37.3 months; HR 0.757) compared with placebo plus fulvestrant in hormone receptor-positive (HR-positive), human epidermal growth factor receptor 2-negative (HER2-negative) advanced breast cancer (ABC) patients who were endocrine therapy (ET) resistant, regardless of menopausal status. Here, we report findings in the premenopausal subgroup of the MONARCH 2 trial.MethodsThe premenopausal subgroup included patients with natural menstrual bleeding who received a gonadotropin-releasing hormone agonist at least 4 weeks prior to study treatment start date and for the entire study duration. Of the 669 patients enrolled in the MONARCH 2 trial, 114 were premenopausal (abemaciclib plus fulvestrant, n = 72; placebo plus fulvestrant, n = 42), and were included in this analysis. The primary objective was investigator-assessed PFS and secondary objectives were OS, objective response rate, and safety and tolerability. Exploratory analyses included time to second disease progression (PFS2), time to chemotherapy (TTC), and chemotherapy-free survival (CFS).ResultsAt the primary objective cutoff (February 14, 2017), median PFS was not reached for the abemaciclib plus fulvestrant arm versus 10.52 months for the placebo plus fulvestrant arm (HR 0.415; 95% CI 0.246–0.698). At the pre-specified OS interim cutoff (20-June-2019), median PFS was 28.6 months in the abemaciclib plus fulvestrant arm compared with 10.26 months in the placebo plus fulvestrant arm (HR 0.477; 95% CI 0.302–0.755). A numerical OS benefit was observed with abemaciclib plus fulvestrant compared to fulvestrant alone (HR 0.689; 95% CI 0.379–1.252, median, not reached vs 47.3 months). Improvements were also observed for the exploratory outcomes of PFS2 (HR 0.599), TTC (HR 0.674), and CFS (HR 0.642) with the addition of abemaciclib to fulvestrant. The safety profile was generally consistent with results disclosed previously.ConclusionsResults of the premenopausal subgroup in the MONARCH 2 trial were consistent with the improved clinical outcomes observed in the intent-to-treat population. The analysis provides support for the use of abemaciclib plus fulvestrant (with ovarian suppression) as an effective treatment option for premenopausal patients with HR+, HER2- ABC who are ET-resistant.Clinical trial registration: NCT02107703. Registered April 08, 2014- Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02107703.

Background:International guidelines for hormone-receptor-positive (HR+), human epidermal growth factor receptor-2 negative (HER2−) advanced breast cancer (BC) recommend sequential lines of hormonal therapy (HT), and only recommend chemotherapy for patients with extensive visceral involvement or rapidly progressive disease. This study evaluated actual physician-reported treatments for advanced BC in Europe.Methods:We conducted a retrospective chart review of 355 postmenopausal women with HR+, HER2− advanced BC who progressed on ≥1 line of HT (adjuvant or advanced) and completed ≥1 line of chemotherapy (advanced). Treatment choice was evaluated for each line of therapy.Results:Of 355 patients, 111 (31%) received first-line chemotherapy, whereas 218 (61%) and 26 (7%) switched from HT to chemotherapy in second and third line, respectively. More patients receiving first-line HT had bone metastases (73% vs 27% chemotherapy). Patients treated with first-line chemotherapy had more brain (12% vs 3% HT) or extensive liver (13% vs 6% HT) metastases. Subgroup analysis of 188 patients who received first-line HT and had de novo advanced BC or relapsed/recurrent disease more than 1 year after adjuvant therapy found that the majority (89%; n = 167) of these patients switched to chemotherapy in second line. However, among these 167 patients, 27% had no significant changes in metastases between first and second line. Among the 73% of patients who had significant changes in metastases, 20% had no brain metastases or extensive visceral disease.Conclusions:Our study suggests that the guideline-recommended use of multiple HT lines is open to interpretation and that optimal treatment for European postmenopausal women with HR+, HER2− advanced BC who responded to HT may not be achieved.

CompLEEment-1 (NCT02941926) is a single-arm, open-label, multicentre phase IIIb study investigating the safety and efficacy of ribociclib plus letrozole (RIB + LET) in a large, diverse cohort who have not received prior endocrine therapy (ET) for advanced disease. We present an exploratory analysis of male patients. Eligible patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC), who had no prior ET and ≤ 1 line of prior chemotherapy for advanced disease, received RIB + LET. Male patients also received goserelin or leuprolide. Primary endpoint was safety and tolerability; efficacy was a secondary endpoint. In total, 39/3246 patients were male. Baseline characteristics were similar to the overall population. Male patients experienced fewer treatment-related adverse events (AEs) and treatment-related serious AEs compared with the overall population; fewer male patients had treatment-related AEs leading to discontinuation, adjustment/interruption, or additional therapy. One male patient died as a result of a serious AE that was not considered to be treatment-related. The most common AE was neutropenia; the incidence of grade ≥ 3 neutropenia in males (41.0%) was lower than in the overall population (57.2%). Median follow-up was 25.4months; median time to progression was not reached in males versus 27.1months for the overall population. The clinical benefit and overall response rates in males were consistent with the overall population. This analysis demonstrates the safety and efficacy of ribociclib in a close-to-real-world setting, supporting the use of RIB + LET in male patients with HR+, HER2- ABC. NCT02941926 (Registered 2016).

PurposeIn the initial PALOMA-2 (NCT01740427) analysis with median follow-up of 23 months, palbociclib plus letrozole significantly prolonged progression-free survival (PFS) in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2−) advanced breast cancer (ABC) [hazard ratio (HR) 0.58; P < 0.001]. Herein, we report results overall and by subgroups with extended follow-up.MethodsIn this double-blind, phase 3 study, post-menopausal women with ER+/HER2− ABC who had not received prior systemic therapy for their advanced disease were randomized 2:1 to palbociclib-letrozole or placebo-letrozole. Endpoints include investigator-assessed PFS (primary), safety, and patient-reported outcomes (PROs).ResultsAfter a median follow-up of approximately 38 months, median PFS was 27.6 months for palbociclib–letrozole (n = 444) and 14.5 months for placebo-letrozole (n = 222) (HR 0.563; 1-sided P < 0.0001). All subgroups benefited from palbociclib treatment. The improvement of PFS with palbociclib-letrozole was maintained in the next 2 subsequent lines of therapy and delayed the use of chemotherapy (40.4 vs. 29.9 months for palbociclib–letrozole vs. placebo-letrozole). Safety data were consistent with the known profile. Patients’ quality of life was maintained.ConclusionsWith approximately 15 months of additional follow-up, palbociclib plus letrozole continued to demonstrate improved PFS compared with placebo plus letrozole in the overall population and across all patient subgroups, while the safety profile remained favorable and quality of life was maintained. These data confirm that palbociclib-letrozole should be considered the standard of care for first-line therapy in patients with ER+/HER2− ABC, including those with low disease burden or long disease-free interval. Sponsored by Pfizer; ClinicalTrials.gov: NCT01740427.